Surgical instrument washer and sterilizer



y 1962 R. JEWELL 3,034,520

SURGICAL INSTRUMENT WASHER AND STERILIZER Filed Jan. 14. 1959 "Mir Pa W52 5 UPPLY FIG-Z Z i IN V EN TOR. B S

M457 1 D d Mu United States Patent Ofifice 3,034,520 Patented May 15, 1962 3,034,520 SURGICAL INSTRUMENT WASHER AND STERILIZER Raymond L. Jewell, Erie, Pa., assignor to American Sterilizer Company, Erie, Pa., a corporation of Pennsylvania Filed Jan. 14, 1959, Ser. No. 786,804 3 Claims. (Cl. 13499) This invention is intended to wash and sterilize surgical instruments. In a preferred form, the washing is effected by a submerged ultrasonic transducer within the sterilizing chamber and simultaneously radiating ultrasonic energy in opposite directions to instruments in submerged trays on opposite sides of the transducer. The sterilizing is effected by high pressure steam which envelops both the transducer and the instruments within the trays.

In the drawing, FIG. 1 is a front view of an instrument washer and sterilizer; FIG. 2 is a section on line 22 of FIG. 1; and FIG. 3 is a detail section through the transducer.

The washer sterilizer is mounted on a frame I carrying an ultrasonic frequency power source 2 and a pressure chamber 3 having its front end closed by a door 4 supported by hinges 5 and held in the pressure tight closed position by a lock 6. The chamber 3 has rigid walls having bursting strength sufiicient to withstand the sterilizing pressure with the necessary factor of safety. 0n the top wall 3a of the chamber is mounted a safety valve 7, a water supply valve 8, and a steam supply valve 9 for steam at the sterilizing temperature at pressure (usually 27 pounds per square inch and 270 degrees F On the bottom wall 317 of the chamber is an exhaust valve 10 for exhausting steam from the chamber and a drain valve 11 connected through a steam trap 12 to a waste line 13 for draining water from the chamber.

Adjacent opposite side walls 14, 15 of the chamber are upper angle supports 17, 18 for an instrument tray 19, intermediate angle supports 20, 21 for a transducer housing 22 and lower angle supports 23, 24 for a lower instrument tray 25. The trays 19 and 25 are open top and bottom and are spaced inward from the side walls 14, 15 of the chamber to permit free circulation of water during washing. The housing 22 for the ultrasonic transducer is sealed water and pressure tight and, as shown diagrammatically in FIG. 3, has flexible upper and lower metal walls 26, 27 in direct contact with opposite ends of a plurality of spaced magnetostrictive transducer elements 28, each driven by a coil 29 supplied by driving power from the ultrasonic frequency generator 2. The power connection is made to the transducer elements through a bushing 30 extending through and sealed to the rear wall 31 of the vessel. The inner end 32 of the bushing is sealed to the ultrasonic transducer housing 22. A conduit 33 leading from the generator 2 to a connection box 34 supplies power to the drive coils 29.

The transducer elements 28 are arranged perpendicular to the flexible metal walls 26, 27. Upon being driven by the coils 29, the transducer elements 28 expand and contract in lengthwise directions, producing simultaneous pulsation in opposite directions and at the ultrasonic driving frequency. The ultrasonic energy is transmitted directly to the water and through the water to the instruments in the trays 19 and 25. The absence of an air gap between the transducer elements and the walls 26, 27 makes the transducer elements efiectively in direct contact with the water for efiicient transfer of ultrasonic energy. The efliciency of utilization of the energy is increased by having the trays on opposite sides of the transducer to take advantage of the radiation in opposite di rections. The walls 26, 27 of the transducer housing can be relatively thin because they are not subjected to bursting pressure and are supported by the transducer elements which are arranged in compression between the walls.

In use, soiled instruments are placed in the trays 19 and 25 which are loaded in the washer on the angle supports. After closing the door 4 and locking it pressure tight, the chamber is filled with water by opening the valve 8. Whether the water level in the chamber is controlled manually or automatically, it is desirable that both instrument trays be completely submerged. A suitable air vent may be opened during filling to exhaust from the chamber the air displaced by the water. A suitable detergent may be added prior to, during, or after filling in any convenient manner. After filling, the ultrasonic frequency power source 2 is activated to supply power at ultrasonic frequency to the transducer 22 which simultaneously sends ultrasonic energy in a downward direction to wash the instruments in tray 25 and in an upward direction to wash the instruments in tray 19. At the end of the desired washing period, the power supply 2 is shut off and the steam valve 9 opened to admit steam to the upper part of the chamber 3. At the same time, the drain valve 11 is opened and the steam pressure which accumulates on top of the body of water in the chamber forces the water rapidly out through the steam trap 12 into the water drain line 13. As soon as live steam enters the steam trap 12, the trap automatically shuts off and steam rapidly builds up in the chamber 3 to the desired pressure and temperature (usually 27 pounds per square inch and 270 degrees B). After a brief sterilizing interval, the steam supply is shut off and the steam exhaust valve 10 is opened to relieve the pressure. After the pressure is relieved, the door is opened and the washed and sterilized instruments are removed.

The apparatus can be used as a washer without going through the sterilizing operation. Likewise, it may be used as a steam sterilizer without the washing cycle. Suitable automatic controls may be provided for all of the operations.

The ultrasonic transducer, because of its two direction- 21 action, works more etliciently. Although it must withstand sterilizing pressure and temperature, the transducer housing design is such that the transducers are directly coupled to the water as is desirable for efiicient radiation. The portions of the walls 26, 27 opposite the ends of the transducers are in direct contact with the transducers and in effect act as though part of the transducers. The

portions of the walls between the transducers do not impede radiation because of their flexibility. The transducer elements are sealed in the housing 22 and protected from the water and steam. Transducer elements other than magnetostrictive may be used. It is not necessary that the transducers be enclosed in a single housing although that is convenient. Each transducer could be separately enclosed and the enclosures mounted in a supporting frame. The transducers need not be completely enclosed. A structure in which only the coils 29 and the wiring are insulated and protected from the Water and steam with the ends of transducers in direct contact with the water can be used and would have the advantage of direct transmission of energy from the ends of the transducer to the water. For small units, only a single transducer is needed.

What is claimed as new is:

l. A washer for surgical instruments comprising a chamber adapted to be filled with water, supporting means for vertically spaced upper and lower trays of instruments, the trays being submerged in thewater and open at the top and bottom, a sealed ultrasonic transducer housing having upper and lower walls, transducer means comprising at least one transducer body bridging the space between said walls with opposite ends of the body between and connected to said walls and alternately expanding and contracting in a direction perpendicular to said Walls and thereby simultaneously radiating ultrasonic energy in opposite directions, means supporting the transducer between the trays with the upper wall of the transducer radiating toward the bottom of the upper tray and with the lower wall of the transducer radiating toward the top of the lower tray.

2. A Washer for surgical instruments comprising a chamber adapted to be filled with water, a door closing the front of the chamber, an upper horizontal support for a tray of instruments, a lower horizontal support for a tray of instruments, the trays being submerged in the water and open at the top and bottom, a sealed ultrasonic transducer housing having upper and lower walls, transducer means comprising at least one transducer body bridging the space between said Walls with opposite ends of the body between and connected to said Walls and alternately expanding and contracting in a direction perpendicular to said walls and thereby simultaneously radiating ultrasonic energy in opposite directions, means supporting the transducer between the trays with the upper Wall of the transducer radiating toward the bottom of the upper tray and with the lower wall of the transducer radiating toward the top of the lower tray.

3. In a surgical instrument washer and sterilizer comprising a sealed chamber having a water supply line for filling the chamber with water, a water drain line in the lower part of the chamber, a steam supply line for filling the chamber with steam, a steam drain line in the lower part of the chamber, valves in the supply and drain lines, an ultrasonic transducer having spaced upper and lower flexible walls and at least one transducer body bridging the space between said Walls and vibrating said walls simultaneously at ultrasonic frequency in opposite directions to cause simultaneous radiation of ultrasonic energy in opposite directions, means for supporting the transducer in the chamber with the upper and lower walls respectively submerged and directed toward the top and bottom of the chamber, means for supporting submerged instrument trays open at the top and bottom and spaced both above and below the transducer Walls for simultaneously receiving said ultrasonic energy, and a steam trap in the water drain line whereby opening the steam supply and water drain valves the steam pressure forces the water out of the chamber until the flow of steam reaches and closes the trap.

References Cited in the tile of this patent UNITED STATES PATENTS 2,289,890 Walter July 14, 1942 2,532,550 Hubbard Dec. 5, 1950 2,623,376 Volk Dec. 30, 1952 2,702,260 Massa Feb. 15, 1955 2,854,012 Murdoch Sept. 30, 1958 

